Potato strip and method of producing french fried potatoes

ABSTRACT

An uncooked strip of extruded potato mix having an elongated body and a polygonal cross section defined by concave sides of predetermined radius of curvature substantially equal to the mean of the longest and shortest dimension of the cross section of the strip meeting at rounded corners, said rounded corners having a predetermined radius of curvature which is substantially equal to about one-eleventh of the radius of said concave sides, the concave sides being deformable by cooking to acquire a flat condition while said rounded corners remain unchanged.

waited States Patent Mines 1 Feb. 29, 1972 [54] POTATO STRIP AND METHODOF PRQDUCING FRENCH FRIED 211 App]. No.5 625,231

3,391,005 7/1968 Babigan ..99/l00 Primary Examiner-A. Louis MonacellAssistant Examiner-William A. Simons Attorney-George A. Rolston [5 7]ABSTRACT An uncooked strip of extruded potato mix having an elongatedbody and a polygonal cross section defined by concave sides ofpredetermined radius of curvature substantially equal to the mean of thelongest and shortest dimension of the cross section of the strip meetingat rounded corners, said rounded corners having a predetermined radiusof curvature which is substantially equal to about one-eleventh of theradius of said concave sides, the concave sides being deformable bycooking to acquire a flat condition while said rounded corners remainunchanged.

5 Claims, 7 Drawing Figures PATENTEDFEBES 1912 29 FIG 5 FIG 7 INVENTORLAURENCE J. ILINES BY fi Maw/WM POTATO STRIP AND METHOD OF PRODUCINGFRENCH FRIED POTATOES The present invention relates to french friedpotatoes and is concerned primarily with the method of producing frenchfried potatoes of a desired cross-sectional shape and particularly inthe cross-sectional shape of a raw strip extruded from a potato flourmix.

Customers of french fried potatoes are often desirous that the potatoesserved to them have a particular appearance which is detennined by thecross-sectional shape of the potato strips. It has been proposed to formthe strips from a raw potato flour mix which is extruded to form thestrips. However, it has been found that frying in deep fat distorts theshape of the raw strip so that the cooked product does not have the samecross-sectional shape which obtained in the strips before cooking.

Thus an important object of the present invention is to provide a methodof producing french fried potatoes which includes the step of extrudinga potato flour mix into strips having a cross-sectional shape, that is,related to the desired shape of the cooked product together with thestep of cooking in deep fat to achieve the ultimate shape desired.

An other object is to provide an extruded potato strip having across-sectional shape which provides a desired cross-sectional shape inthe cooked product.

The most popular shape of french fried potatoes is a square crosssection. If a raw strip is of a square cross section, cook ing thereofdistorts the sides into convex shapes which constitute a materialdeparture from the square shape that is so popular. In accordance withthe present invention, the potato flour mix is extruded into a striphaving four concave sides which meet at rounded corners. The curvatureof these sides is predetermined so that cooking deforms them into thestraightsided structure desired in the ultimate product.

It has been found, as a practical matter, that is is impossible topreserve square or sharp corners in a potato strip. Thus an importantfeature in the invention is to provide a square strip of the characterabove noted which has rounded corners. Moreover, it is important thatthese corners be of such a curvature as to practically precludeimpairment thereof during the extruding and subsequent cookingprocesses. Thus the relation of the rounded corners to the dimensions ofthe strip and the curvature of the sides is of importance. Also theradius of curvature of the concave sides should be properly related tothe dimensions of the strip.

Some of the more detailed objects and advantages of the invention suchas those which arise in connection with carrying out the above-notedideas in a practical embodiment will, in part, become apparent and inpart be hereinafter stated.

For a full and more complete understanding of the invention, referencemay be had to the following description and accompanying drawing,wherein:

FIG. I is a perspective view of a raw potato strip shaped anddimensioned in accordance with the precepts of this invention;

FIG. 2 is a perspective view of the potato strip of FIG. 1 after cookingin deep fat;

FIG. 3 is a diagrammatic view depicting the shape of a cross section ofthe raw strip before cooking;

FIG. 4 is another schematic view showing the cross-sectional shape ofthe cooked strip as superimposed on the shape of the raw strip;

FIG. 5 is a view similar to FIG. 3 but of a raw strip of triangularshape;

FIG. 6 is a view similar to FIG. 4 depicting the strip of FIG. 5 aftercooking and as superimposed on the raw strip, and;

FIG. 7 is a perspective view of a portion of the extruding apparatusillustrating how the strips are extruded in multiple.

Referring now to the drawings, and first more particularly to FIGS. 1 to4 inclusive, a cooked potato strip is illustrated in FIGS. 2 and 4, thisstrip has a cross section defined by sides I0, ll, 12 and 13, all ofequal length thereby defining a square cross section.

The sides 10, ll, 12 and 13 are joined at rounded corners 15.

Referring now to FIGS. 1 and 3, the uncooked strip from which the stripL was made is identified in its entirety by the reference character R.It is defined by four sides of equal size and shape which are identifiedat 16,17,18 and 19, all being joined by the rounded corners I5. It willbe noted that the sides 16 to 19 inclusive are arcuate with the side 16corresponding to the side It) and the side 17 to the side 11, side 18 tothe side 12 and the side 19 to the side 13.

The longest dimension of the raw strip R is depicted in FIG. 3 andrepresented by the reference character A. It is, in fact, the diagonalof the square The shortest dimension of the strip R is represented by Band is the distance across the shortest distance between opposed sides16 and 18. Of course. this same distance would obtain between the sides17 and 19.

The radius of the arcuate sides 16 to 19 inclusive may be represented bythe reference character r and the radius of the rounded corners I5 bythe reference character r'. Purely by way of example, one set ofdimensions which may obtain in the strip R are given as beingillustrative of the proportions which obtain between the radii r and rand also the ratio of these radii to the dimensions of the strip R.

Thus if the dimension B is two hundred and seventy-five thousandths ofan inch, dimension A will be four hundred and ten thousandths of aninch. The curvature of the arcuate sides I6 to 19 inclusive, which isrepresented at r is determined by a radius of eleven thirty-seconds ofan inch and the curvature of the corners represented by r is determinedby a radius of one thirty-second of an inch.

Thus it may be stated that the radius of the curvature of the corners isabout one-thirteenth of the largest dimension of the strip, or aboutone-ninth the smallest dimension, also. The radius of the curvature ofthe arcuate sides r is about ll times the curvature of the roundedcomers r. Moreover, the radius of curvature of the arcuate sides issubstantially equal to the mean or average of the longest and shortestdimensions of the strip.

Referring now more particularly to FIG. 7, a potato flour mix is thereinillustrated at 20 as being received in a container 21 having a bottomextrusion plate 22 formed with apertures 23 of the shape correspondingto the raw strip R.

In practising the method of the invention, the potato flour mix is firstprepared and introduced into the container 21. Pressure is then appliedthereto to extrude the strips R in multiple through the openings 23.These strips will have the concave side shape illustrated in FIGS. 1 and3. They are now cooked in deep fat for a prescribed period of time,whereupon the sides are distorted and caused to swell out into thestraight sided formation illustrated in FIGS. 2 and 4.

FIGS. 5 and 6 illustrate a potato strip which is of triangular shape,thus FIG. 6 illustrates the form of the finished product including thestraight sides 24, 25 and 26. These sides are joined at the roundedcorners 27. In FIG. 5 the raw strip is shown as having the arcuate sides28, 29 and 30 which are joined at the rounded corners 27. It is believedthat substantially the same relation between the curvature of therounded corners 27 and the arcuate sides 24, 25 and 26 will obtain asdescribed above, in connection with FIGS. 1 to 4 inclusive.

The basic factor underlying the present invention is the recognition ofthe phenomenon that the shape of a raw strip can never be maintainedduring cooking. It must be designed in advance to give the shape desiredin the finished product. Also, that when any type of a polygonalconstruction is desired, such as one of square cross section the roundedcorners must be of a curvature that is properly related to the arcuatecurvature of the sides and the maximum and minimum dimensions of thestrip.

While preferred and specific embodiments of the invention arehereinbefore set forth, it is to be clearly understood that theinvention is not to be limited the exact steps, dimensions and shapesillustrated and described because various modifications of these detailsmay be provided in putting the invention into practice within thepurview of the appended claims.

What is claimed is:

1. An uncooked strip of an extruded potato mix, said strip comprising anelongated body having a polygonal cross section defined by concave sidesof predetermined radius of curvature substantially equal to the mean ofthe longest and shortest dimension of the cross section of the stripmeeting at rounded corners said rounded corners having a predeterminedradius of curvature which is substantially equal to about oneeleventh ofthe radius of said concave sides; the concave sides being deformable bycooking of said body to acquire a substantially flat condition whilesaid rounded comers remain substantially unchanged.

2. The potato strip of claim 1 in which said polygonal cross section hasfour sides and four comers.

3. The potato strip of claim 1 which is of square cross section and inwhich the rounded corners are arcuate as determined by a radius which issubstantially one-eleventh the radius that determines the curvature ofthe concave sides.

4. In a method of producing french fried potatoes, the steps of:preparing a mix from potato flour; extruding said mix into multiplestrips each having an elongate body of a polygonal cross section shapedefined by concave sides of predetermined radius of curvature meetingsubstantially equalto the mean of the longest and shortest dimension ofthe cross section of the strip at rounded comers; said rounded comershaving a predetermined radius of curvature which is substantially equalto about one-eleventh of the radius of said concave sides; and thencooking said strips in deep fat whereby said curved sides are deformedinto a desired substantially flat condition while said rounded comersremain substantially unchanged.

5. The method of claim 4 in which the extruded strips have .four saidconcave sides and four said rounded comers.

2. The potato strip of claim 1 in which said polygonal cross section hasfour sides and four corners.
 3. The potato strip of claim 1 which is ofsquare cross section and in which the rounded corners are arcuate asdetermined by a radius which is substantially one-eleventh the radiusthat determines the curvature of the concave sides.
 4. In a method ofproducing french fried potatoes, the steps of: preparing a mix frompotato flour; extruding said mix into multiple strips each having anelongate body of a polygonal cross section shape defined by concavesides of predetermined radius of curvature meeting substantially equalto the mean of the longest and shortest dimension of the cross sectionof the strip at rounded corners; said rounded corners having apredetermined radius of curvature which is substantially equal to aboutone-eleventh of the radius of said concave sides; and then cooking saidstrips in deep fat whereby said curved sides are deformed into a desiredsubstantially flat condition while said rounded corners remainsubstantially unchanged.
 5. The method of claim 4 in which the extrudedstrips have four said concave sides and four said rounded corners.